{"cells":[{"metadata":{"_uuid":"8f2839f25d086af736a60e9eeb907d3b93b6e0e5","_cell_guid":"b1076dfc-b9ad-4769-8c92-a6c4dae69d19","trusted":true},"cell_type":"code","source":"import os\nimport cv2\nimport skimage.io\nfrom tqdm.notebook import tqdm\nimport zipfile\nimport numpy as np\n","execution_count":null,"outputs":[]},{"metadata":{"trusted":true},"cell_type":"code","source":"TRAIN = '../input/prostate-cancer-grade-assessment/train_images/'\nMASKS = '../input/prostate-cancer-grade-assessment/train_label_masks/'\nOUT_TRAIN = 'train.zip'\nOUT_MASKS = 'masks.zip'","execution_count":null,"outputs":[]},{"metadata":{"_uuid":"d629ff2d2480ee46fbb7e2d37f6b5fab8052498a","_cell_guid":"79c7e3d0-c299-4dcb-8224-4455121ee9b0","trusted":true},"cell_type":"code","source":"sz = 128\nN = 16\n","execution_count":null,"outputs":[]},{"metadata":{"trusted":true},"cell_type":"code","source":"def tile(img, mask):\n    result = []\n    shape = img.shape\n    pad0,pad1 = (sz - shape[0]%sz)%sz, (sz - shape[1]%sz)%sz\n    img = np.pad(img,[[pad0//2,pad0-pad0//2],[pad1//2,pad1-pad1//2],[0,0]],\n                constant_values=255)\n    mask = np.pad(mask,[[pad0//2,pad0-pad0//2],[pad1//2,pad1-pad1//2],[0,0]],\n                constant_values=0)\n    img = img.reshape(img.shape[0]//sz,sz,img.shape[1]//sz,sz,3)\n    img = img.transpose(0,2,1,3,4).reshape(-1,sz,sz,3)\n    mask = mask.reshape(mask.shape[0]//sz,sz,mask.shape[1]//sz,sz,3)\n    mask = mask.transpose(0,2,1,3,4).reshape(-1,sz,sz,3)\n    if len(img) < N:\n        mask = np.pad(mask,[[0,N-len(img)],[0,0],[0,0],[0,0]],constant_values=0)\n        img = np.pad(img,[[0,N-len(img)],[0,0],[0,0],[0,0]],constant_values=255)\n    idxs = np.argsort(img.reshape(img.shape[0],-1).sum(-1))[:N]\n    img = img[idxs]\n    mask = mask[idxs]\n    for i in range(len(img)):\n        result.append({'img':img[i], 'mask':mask[i], 'idx':i})\n    return result\n","execution_count":null,"outputs":[]},{"metadata":{"trusted":true},"cell_type":"code","source":"x_tot,x2_tot = [],[]\nnames = [name[:-10] for name in os.listdir(MASKS)]\nwith zipfile.ZipFile(OUT_TRAIN, 'w') as img_out,\\\n zipfile.ZipFile(OUT_MASKS, 'w') as mask_out:\n    for name in tqdm(names):\n        img = skimage.io.MultiImage(os.path.join(TRAIN,name+'.tiff'))[-1]\n        mask = skimage.io.MultiImage(os.path.join(MASKS,name+'_mask.tiff'))[-1]\n        tiles = tile(img,mask)\n        for t in tiles:\n            img,mask,idx = t['img'],t['mask'],t['idx']\n            x_tot.append((img/255.0).reshape(-1,3).mean(0))\n            x2_tot.append(((img/255.0)**2).reshape(-1,3).mean(0)) \n            #if read with PIL RGB turns into BGR\n            img = cv2.imencode('.png',cv2.cvtColor(img, cv2.COLOR_RGB2BGR))[1]\n            img_out.writestr(f'{name}_{idx}.png', img)\n            mask = cv2.imencode('.png',mask[:,:,0])[1]\n            mask_out.writestr(f'{name}_{idx}.png', mask)","execution_count":null,"outputs":[]},{"metadata":{"trusted":true},"cell_type":"code","source":"img_avr =  np.array(x_tot).mean(0)\nimg_std =  np.sqrt(np.array(x2_tot).mean(0) - img_avr**2)\nprint('mean:',img_avr, ', std:', np.sqrt(img_std))","execution_count":null,"outputs":[]}],"metadata":{"kernelspec":{"language":"python","display_name":"Python 3","name":"python3"},"language_info":{"pygments_lexer":"ipython3","nbconvert_exporter":"python","version":"3.6.4","file_extension":".py","codemirror_mode":{"name":"ipython","version":3},"name":"python","mimetype":"text/x-python"}},"nbformat":4,"nbformat_minor":4}